Putting Love Back into Animal Mating

By Ken Kawata

Much has been talked about breeding wild animals in zoos for preserving the species, thereby contributing to the world-wide efforts toward conservation of nature.  Toward this common goal, zoo biologists have tried various methods, utilizing the cutting-edge technologies.  They have worked on many species from large mammals with great public appeal, to small and not so iconic ones such as toads and insects.  The operating principle is based on what makes sense the most, scientifically, in the eye of biologists.  It is the "Father Knows Best" approach; to put it another way it represents a human-centered (anthropocentric) method.

Unlike the agricultural or medical science, zoo animal management programs begin with a small sample size.  When mating zoo animals, the number of animals and genetic information from each animal become critical.  In order to maintain a genetically diversified captive population, it is vital to avoid inbreeding.  In a breeding program individual animals have their ID numbers, and in the process of match-making, two ID numbers are put together.  Thus, number-crunching is a part of planning; there is a tendency for zoo biologists to become "computer biologists" and for animals, to become an abstraction.  However, this process can leave out the requirements of the breathing, living animals.  Naturally, behavioral aspects such as "chemistry" and compatibility of animals must be added to the equation.  It is refreshing, in this aspect, that biologists at Brookfield Zoo have turned the tables, to focus on the individual animal. 

A female blue-gray tanager, a tropical bird, lives in a large enclosure, while three males are kept in separate cages on the other side.  They can see each other.  Cameras record their movements, eventually, to indicate which male she will choose to mate.  This is the process that takes place in the wild.  This is a switch from the traditional way in which the breeding program manager tells animals: "You, and you, get together and make babies."  In the wild, a female tanager's choice may be based on appearances such as brighter colors or longer tails and at this zoo, biologists wish to let the bird select her "true love".  It is a departure from the "arranged marriage", a product of number-crunching for the best genetic benefits.  It is hoped that this approach will lead to results such as improved parental care, thus yielding crucial answers to species survival.  Possibly, this new strategy could apply to other birds and animal groups in captivity, including mammals and reptiles.